North Korea yesterday renewed threats to launch a “sacred war” against South Korea, indicating cross-border ties will remain icy despite Pyongyang’s surprise nuclear deal with Seoul’s close ally Washington.

The North’s agreement to freeze some nuclear and missile activities in return for massive US food aid has raised cautious hopes of eased tensions under its new young leader Kim Jong-Un.

In statements released late Wednesday announcing the deal, both Pyongyang and Washington pledged to work for better relations. But yesterday’s comments from the North’s supreme military command struck a different tone with the South.

The command accused South Korean troops of displaying slogans or placards slandering the North’s top leaders at their barracks, shooting ranges and other military facilities.

The command “solemnly declares once again that it will indiscriminately stage its own-style sacred war to wipe out the group of traitors”.

“Those who hurt the dignity of the supreme leadership of the DPRK even a bit will find no breathing spell in this land and sky,” it said.

Pyongyang made similar threats last year when South Korean reservists were found to be using pictures of the ruling Kim dynasty as rifle-range targets. The South says that practice has been stopped.

Pyongyang has taken a consistently hostile tone towards Seoul since Jong-Un took over after his father Kim Jong-Il died of a heart attack on December 17.

Last Saturday it threatened a “sacred war” over US-South Korean joint military drills, describing them as a “silent declaration of war”.

The North vows never to deal with the South’s conservative leaders, accusing them of trying to spark a war and rejecting appeals for dialogue. Yesterday it compared them to “a mad dog getting more ferocious before meeting its end”.